Process of preparing cyanogen compounds.



J. E. BUGHBR. l PROCESS OP PBEPARING GYANOGBNGOMPOUNDS. APPLIU'ATIVQFFILED IAB. 9, 1914 1,1 16,559. Patend Nov.1o,194'.

^ Inventor-I.,

7 v waarnemers-T l 1,116,559. Original'applieation 1ed December 1B,1912, Serial 110.7371368. Divided and this'applicatow filed liarcli YSerial No. 8{3,306. *"i'i `proved process of preparing, if desired,substantially ure cyanogen compounds and deirivatives t erefr'om,together with valuable JOHN E. BUCHEE, or oovEN'rEY, RHODEisLAND,AssIGNoii'rhofifrriaoeiiiifpaonucrs COMPANY, OE rnovIDENOE, RHODEISLAND, e GORPOEATION'OE EEOD'E ISLAND.

.To all who/nit may concern:

B e it known thatI, JOHN E. BUOHER,

citizen of the United States, residing at Coventry, in thecountyx of..Kent and State of' Rhode Island, havel invented certain new andusefulIniprovements in v Processes of Preparing Cyanoge'n Compounds, ofwhich the-following is aspecication.

This invention relates to the fixation of nitro-gen and moreparticularly to an .im-

'y-produ'zts incident to the production of such a compound or'.compounds.

The present. process is, in certainofits aspects, Vto be regarded as animprovement upon the processes described in my pending-g have beenobtained by lixiviating the crude lfurnace-productsfin which they areformed, :with Water by absorbing cyanogen or hydroapplication for U. S.Letters Patent, respectively designatedSerial No. 711,211, tiled f July24, 1912,@1 serrano. 726,924; and October 2 1, 1912; and the presentapplica.

application for Lettiorrisfa -division of my ters Patent, Serial No.737,368, filed Dec. .18, 1912, and entitled Process of preparingcyanogen compounds.

One of the features of importance involved in the present process is theutilization of distillation broadly and particularly of distillationunder diminished pressure during the course of the eyanogen compound'producin'goperation, asa means for facilitating the production orpreparation of pure or substantially. pure cyanogen compounds, e.' g. v

sodium cyanid. Such -procedure is of very great importance when usedl inconnection with' the synthetic formationof cyanids and 'the like as`.`set forth atlength in" my said y pending applications, and especially inthat designated Serial No` 726.924. 'Insaid application I 'haveintimated that distillation lof cyanid from the reactive masscontainingl catalytioimaterial is feasible and I -herein describemoreparticularly an advantageous way of lell'ecting such distillation. Vhilethis' operation is ofparticular value in connection with my saidpreviously described I do not Wish to 'be limited there .he directlyconcerned in the reaction in question, are used. It may also injure, or.indeed in some cases render wholly useless -many of the catalyticmaterials available for,

where in certain of the appended claims I specifically include as stepsin the process certain of those more particularlyset forth in saidpending applications; since I am aware that the distillation of cyain ds1n the manner hereinafter described not only .I PROCESS OE PEErAnINGOYANQGENOOMPOUNDS.

Specification of Letters Patent. Pgtgngd Nvplof,

facilitates the production of' sucht substances insa-#form =in whichthey are substantial-ly immediately ready for use Without furthertreatment, but further is .of value in eifecting a purification ofcyanids produced by other methods 'than those described in my saidapplications so that it may even be applied .to some of the very impurecommercial by chemical reactions.

x I have-found in my study .ofi the art that with but few importantexceptions, 'cyanide-A lcyanic acid 1n aqueous alkaline solutions; byextracting them with alcohol; etc.; followed by subsequentcrystallization fromthe resulting solutions. `.This -is especially trueof the rather loosely so called synthetic' procnitrogen for theproduction of the cyanids.

The above methods ol purification depending upon lixivia-tion andcrystallization are open to many serious objection, Such 'as thepoisonous properties of eyanogen com- 'pounds` the decomposition of thecyanids in Water solution, expense, the sparing solubil ity ofcyanids inalcohol, inflanimabihty of the alcohohetc. 'In some cases thelixiviation vresults in a loss of alkali; and,V in substan- "tia'lly anycase the reaction products must be allowed to cool before they can belixiviat'ed. Also the moist residue from lixiviation must in certaincases be freed from .Water before it can again -be used for thepreparation of' another quantity of cyanid, because water will reactdeleteriously Whenimaterialsisuch as potassium, sodium, or lithium,which may :tain nitrids, etc.

claims.-I

I am aware that various modifications and changes may be made in myprocess and the manner of conducting the same, without de- Karting .fromthe spirit of my invention and ence desire to be limited only by thescope of said claims considered broadly in the light of my disclosure. y

In the .accompanying drawing which forms a part hereof and in which likereference characters designate like parts throughout the several views,I have exemplified an apparatus suitable for the efi'ectuation of myprocess, but it will be understood that 1 am not to be limited in anyway to this exemplification since various other forms and types ofapparatus are well adapted to the process in question.

Referring to the drawing: Figure 1 is a longitudinal vertical section ofa mulile furnace with retorts in position therein. Fig.2 is an endelevation of said furnace, the blast lamp being omitted forconvenience'of illustration. Fig. 3 is a fragmentary section taken online III--III of Fig. 1. Fig. 4 is' a similar section of a retortadapted for the use ofair in the process.

Brickwork or other suitable material may be employed in the constructionof the muflle 1, and one or more pipes 2, serving as retorts, may extenddirectly therethrough. Couplings or unions 3, serve to connect the endsof the retorts, or the extensions '2 of the same, hereinafter referredto, to the pipes 4-45; those designated 4 being the pipes for supplyingnitrogen or air, as the case may be. The gases, notably carbon monoxid,evolved during the operation of the process are conveyed away. via pipes5 5. A blast lamp 6, or other suitable source of heat may be disposed inthe preferably open end of the muffle, and this apparatus should, ofcourse, be capable of heating the jretorts up to the reactiontemperatures employed.' i

Assuming that the process is to be conducted in such fashion as topermit the use gf air, the latter is led in through pipes 4 andpreferably first encounters one ormore masses 7 of charcoal or othersuitable oxygen'r consuming material. These masses preferablysubstantially fill the pipes at the points where they are disposed sothat all of the air is obliged to pass therethrough. I prefer tointerpose wire gauze spacing or supporting screens 8, or the like,between the charcoal and the body of the reaction mixture'9 which isnext encountered by the gases flowingthrough the pipe or retort; sinceit is desirable to keep the charcoal away from 'the charge. VDuring thecourse of the oper-- ation, the alkali metal will befevolved in themanner hereinafter described, andif the charcoal is in contact withthereactive mass or mixture, it may, by capillary action, or

from any other cause,.remove a portion of l such alkali metal from saidmass and 'thereby reduce the yield.

The mixture 9 preferably consists 'of pulverulentcoke, graphite,charcoal, coal, or the like, very intimately. mixed -with finely dividedcatalytic material, e. g. iron, and sodium carbonate or otherinexpensive source of the metal forming the base of the cyanogencompound sought, or to be incidentally formed durin the operation.

If nitrogen be used instead of air, the

charcoal screens or masses 7 may, of course,

be omitted.

The extensions or pipes 2 may be coupled direct to the 4exit ends of therespective re` torts by couplings' or unions 3, and to the pipes 5 bycouplings 3, in such manner as to be individually readily removabletherefrom without disturbing the remaining parts of the-apparatus.

Each of the pipes 5 is connected by a pipe 10 with a pipe 11 leading toan `,exhaust pump 12, or other suitable device by means of which avacuum or partial-vacuum can be created in the retorts; the several setsof valves 13, 14 and 15 l, roviding means for preventing an influx o airor other gas into the particular retort or retorts in which it isdesired to effect a reduction of pressure below that ofthe atmosphere.Thus, after the formation of a sufficient vield of cyanid in thereactive masses 9 has been effected, valves 13 and -15will be closed andthose designated 14 will be opened; the exhaust pump, of course, beingin operation. The cyanid will distill out of. the masses 9, at thetemperature of the operation, and will condense in the extended endrelatively cool tubes 2', depositing as a clear liquid which sclidifiesinto glass-like masses or lumps. It may even be cast in molds to formsticks of substantially pure cyanid. When sufficient cyanid has beenobtained in this manner, the blast lamp may be shut ofi', the valves 14closed and the tubes or sections 2 removed, separately if desired, byloosening the couplings at the `respective ends thereof.

The retorts and condensing tubes may be made of any suitable materialbut itis important in this connection to consider the rle' which certainsubstances', such as iron are adapted-to )lay under. conditions to whichI shall re er, in decomposing cyanogen compounds, e. g. sodium cyanid;iron, for example by reason of its ability, at a relatively hightemperature. to absorb or separate carbon from such compounds. Failureto notethis )henomenon possibly explains the failure oi certainfknownproc- 1,116,155@ I i l L s?.

:esses having for their obit ct the synk C gto production, or thepurification', of cyanld's.-

The action 'of a material capable' of dissociating the cyanoaen radical1s exempli 5 fied in the following equation Y (-1) l exon-mn:

` In said application, Serial Number 726,924, "'1 have shown thatquantitative yields of Aalkali cyanids can be obtained by heatlng alkalicarbonates with iron and carbon in a current of nitrogen underconditions which I shall. herein briefly review, and since, in

view of the foregoing equation, it is possible to heat oyanid withcarbon-free iron so as to 'elect aquantitative,decomposition of theo`cyanid,-itfollo ws, conversely, that when the ironis'suliicientlycarburized, no decomposition should take place. Pursuaintgtothis, I havefound that sodium cyanid as AWell as potassiiunfcyanid can bedistilled'readily, even atatmosphericpressure, and Withoutsensiblefdecomposition, in receptacles com# 25 posed of suicientlycarburized iron; which v material `is principally of value on account ofitsjchapness as well Vas its'durability,

and abilit 1 to withstand the temperatures at which the operation can beconveniently conducted.y It is possible to elfect the cyaniddistillation in vessels of hard glass, quartz, or the like; while ironapparatus lined with a substance not capable of decomposing alkalifcyanids, e. g. copper,- may also, ot

course, be used for the distillation of' the alkali cyanids underdiminished pressure. If iron a paratus be used, the-iron parts subjectto contact with the hot cyanid vas pors or lixiid will in time becomesuffimtgciently c ar urized vby the action of' the fcyanid itself,`afterwhich the distillation may'be advantageously conducted -in suchapparatus.- Considering next thc. reactive materials used in theprocess, the manner of disposing them in the retortor retorts, and thereactions which take place therebetween,

,I may cite, preliminarily, -the following equation, taken from my saidapplication Seriall Number 726,924.

vThis equation is, yit will be observed, prac! tically the reverse ofequation 1;v the direc' my disclosure in said application wherein.

certain experiments are set forth at length, the results of whichdemonstrate that from about 7 00 C. (roughly) substantially up to '5 theeuteetic 'polnt of the carbon dissolving 'catalytic material, alkalicyanide vmayj be producedfrom,l for example, alkali' carbon ates,hydrates, or the like', free nitrogen and carbon, through theinstrumentality or termediacyof said catalytic material while the latteris in solid form; The.' preferred catalytic material is iron which 'is avmostV efficient solvent for carbon; and the.4 pre ferred form of thiscatalytic material is the oneexposing the greatest practicable catalyticsolution surface compared-to the volv ume of said material, e. nelypulverulent.

I also lsetforth at length in my last mentioned'application 'thedesirability of not only providing such anenor'mouslyextended 80solution surface, but further 'the advantages of maintaining saidsurface, both asregards the 4.maintenance of. an adequate supply ofcarbon in solutipntherein and further as to 'the physical maintenanceofsaid surfaceby g5 conducting the operation, where asolid catalyzer wasemployed, at temperatures materially below the eutecticlpoint of said`material when containing preferably, subs tantially its maximumcarboncontenti vl'.lherein 90 were also shown the advantages ofdisposing themassof reactive material comprising the alkali metal carbonate (forexample), .car bon l(orI carbonaceous material), and the finely powderedcatalyz'er, intimately mixed 95 in such fashion as to no't'only maintainthe carbon supply in the solution surfaces or surface, but to `furtherprovide requisite porosity in a-suflicientA extent of said mass toenable the free nitrogen to ade- 10 quately penetrate thereinto; andtoalso provide by capillary action a relatively cuormously extendedreactive film surface,.tl1 e latter consisting of thefalkali metal.'supplyl in'gunaterial, fuzclehcit, liquid .sodium car- 1'( bonate, drawnup (orretained) by thewic'k like action of the porous portions of thereactive mass, from the bulk of said carbon ate held by gravity inthelower portions of .said mass. lI-'referred in saidv case, lalso, to 1]the desirability of maintaining an adequate supply of nitrogen wherebytofacilitate the Vliberation of alkali metal vapor from the compoundconstituting the source `of the same, by `reducing the vapor pressure ofsaid 1l metal; the nitrogen current not only serving tomeehanicallyremove said vapor but also chemically removingthe same. bycomv biningtherewlth and with carbon at the solution surface, when saidsurface was dis- 12 posed at the place of liberationof said metal'. A

'As I have herein previously indicated, the possibility 'ofcyaniddistillation from the residue 'of the cyanid forming reaction 1fwas considered in said application, and attempted in my comparativelyearly work upon this subject. At atmospheric pressure,

however, the boiling point ci? the more. conlmonl `uscdc anids e. sodiumand otasA l iron, on account ofthe melting` ofthe carburizediron. y

mated, however, with care, the distillation can be madeeifecti've' evenat, atmospheric of a considerable current .saura-n.1..

so that I fouiid 'itinex fgmphae (.orjuie like) and As' -IA havevpreviously intipressurqwhen conducted in properly car-l urized ironreceptaclesl v.Even the lowering ofthe partial .vapor pressurebyLtliepaSSage ofpni'trog'em' which procedure wasat first resortedtouponencontaining residues ofthe reactive mass to.

v in; thel diminished press y tacle being producedfby meanspcf'gan. eAcient vacuum. or vexhaust'V pump 'zand-. the re` vby way of I closed atone end andcontainingafmixture tube served to protect the copper inaSS,collected as a countering this diiiculty,`I found fails to remove theeyanid from the mixture inprac tical quantities, at teijiiperatures'somewhat below the melting point of cz'opper.` :I solved j theproblem', however, finally,` as I have already-indicated, by subjectingthe -cyanid distillation at a -reducedordiininished 'pres-v sure, thedistillationgbeing preferably effected 'directly in ,the retortlandai-after the formation of a properyi-eld ,ofeyanidthere--l tortmeanwhile l,beingadequately' heated.'

The result wastex'tremelysatisfactory; the yanid distillingb out-ot theiron-.graphite 'mass' (iro'n' being the'c'a'talyfticnnateiial,mdAv`face, to` be mixed "with anotherI charge of graphite thesouice ofAcarbon,{infthis instance) quantitatively at temperatures* veryconsiderablJ below the melting point 'of copper.U 1. f The followingexperiment ii'iafyfhegivenI example. A thin copper tube,

of sodium cyanid, produced '..from'the Aaction of nitrogen on` sodium"carbonate, graphite and iron, andthe otherl end connected with:inefficient vacuum o'r exhaust pump.l The loutefr iron froin-oxidationand also from any 'tendency to collapse under the electiveA externalpressure developed. The'tube was then heated-in a furnace to Uponcooling and opening said tube, it was found that cyanid had distilledfrom the ool Aof liquid in th'e colder part of the tu and finallysolidified (in this instance) to a' mass which was so clear andtransparent that fragments ofV it could not be told, oi hand, from'fragments of clear glass until water was,

added.A Titration with a solution of silver nitrate indicated that thespecimen contained 99.9 per cont. ofsodium cyand and the solution gayenoprecipitate with caledient eated mass; while,

used. Th "which remained in4 thetube wasv lixiviated with"water'andfound-'to be so-- free from. alkali compounds 'that'V the resulting.aqueous silver.nitrate or it give :anyl

jeyanidsf 'alkali' cyanid4 or Icyanids it is 'even v'possible tojadmitthe-'new charge hydrate or other' 'sol'ir'c'e ofthe alkali metal in .amolten Ior 5 1 ture. i'n the t'ube.

wasiforced into 'an iron l able'char'gin' -an'd tube. This iron tube wasclosed at one end -mode'of operating 1020 C. for a shorttimer/,underdjminished' pressure inthe interior thereof.l

l1,116,151@ l 'I' i oiumsliydroxid. This showed `the cyanid to be freefrom'alkalicarbonates and to besulo# stantially. chemically' pure. :mentat a temperaturebelow the 'point of copper, proves that-.woman veryThis' experi'- .melting easily'produce pure cyanid froinimixtureOfanalkalicoinpound or compounds, iron andl graphite, in' vasuitablereceptacle, by passing av curi-ent of nitrogen gasover;the

thereafter, bysimply shutting o' the nitrogen and opening th l can 'bedistilled quickly from the hot mass andcollected as pure liquider solidcyanid in a receptacle suitably connected with the apparatus. There isno.neces'sity for opening the apparatus with consequent ldanger i of.oxidation vand cooling of tlie charge; or

for lixiviation; and further there, is node-ngerof attacking the copperliningsl of the apparatus,

residue 'of iron and graphite solution .did not 'give any'\precipitatewith c alciumjhydroxi'd nor did prussian 'blue'vtes't-. -It must hence',have-'been l'substai'i'tially free from .and carbonates." "Moreover,-the iron-grap'hite` residue leftlfrom such a dis#l tillation is lnot'lc'aked yand is in'excellentcon# dition; as regards the catalyticsolution sur- L connection" to the vacuum pump, the cyanid if this bethe liningmaterial.

alkaliy ca rbon'ate or carbonatjs" and used Afor 1 the production ofanother portion of the sought. Indeed,

excellent control-and provided that a suitcan be renewed,'witho'uthaving to c ool the.

.tube -or'e'ven' to remove its contents. Tlic alkali carbonatesfmayalsobe distilled under'diminished pressure' into the catalytic vmixture;-thusdeveloping still Jfurther the the process set forth'in mysaidflas'tnientioned application'jwherein it 'was shojyn'tobepracticable to convey the'alkali metal to ayrelatively rein'otecarboncontaining catalytic' surface,either as av vapor of sz id metalor as avapor of 'acompound of the same.

. I have also distilled the cyanidithe reaction mixtureuatllOOO? C; Ainhard glass' tutes sealed at one end and placed in an' iron tulle; Theglass' tubelasted longr enough for part` of the 'cyanid todistil fromthe mass.,

With the glass 'havealways obtained considerable metallic sodium, whichbeing more volatile than the cyanid, separated out in The process isthus under l mixing device. be ,providedeven' t e graphite vor carboncharge' I 'Tfr-'in probably liquid form still farther from the heatedzone of the tube. This liberation. of sodium due-to the contactj'of thevapor* with the ironouter or containing tube, after theglass had partlymelted. Sodium was notliberated"thencopper tubesA were em-.plo'yed'iinless .there iras some unchanged `sol l dium carbonate presentin the chargeim-' The abovecitcd .experiments show that- .underdiminished pressure alkalicyanids can .be distilled efficiently from amass of iron-graphite? mixturer at temperatures,

, physicall changes combined, as is-shownin the.following'ekamples`.(yariarxiicls, suchas that' otcalcium, maybe'tr'eated with car-f.

' bOnandalt tohormcyanids: 1

land the; :cyanidanay be distilled under `diminished pressure .from .theinass. Sulfocyanids-may be heated directly with and cyanide: Y

Thelalkalicyanid'cani then be distilled from the residues ofl thereaction.` Also ferrocyanids-and 'fcrricyanids canpbe heated to'-f01m"yanids,.thus: i

Simultaneously or later the cyanid. formed can -be 'distilled u'deradiminished pressure.'Y amixture of sodium carbonate,

` ironand graphite and cyanid heated under composes in-:partto i thuskpurifying the cyanid.

`material andthe carbonate or the likebe in excess, suiiicient yield ofcyanid may he ef-A ;l'ectedjto warrant the separtionlof the samer" 'bonmonoxid.;

diminished pressure to distil the cyanid, de,-

f yield sodiumuand car-I Iheseg..eXamples will serve to illustrate.

how effectively the method .can be used l 55,; chemically as wellasphysically to purify and topreparecyanids.

Referring agam to the apparatus given by way of exemplifcation, it isobviousin view of. .th e foregoing that if the charge of.graphiteor'other suitable carbon supplying from the residues lof the.reaction ,and 'fi-oni `the carbon presentin which,'the nitrogen suppliedbythe {stream ofthe same, and'tliej' still unacted upon;4such-preparatir'm beingj veiiected in the manner indicated.

Thereafter the exhaust pump may be stopped, the .valves 14 closed, andvalves 13 and 1 5. again opened, to 4resume tne-forma iorination andseparation ofthe cyanid may.

be alternated, whileboth steps of .the proc-*j ess are efectuatedinthesame pieceof'ap-'- paratus and' at substantially the same tem'`perature, if desired.

I ani of the opinion also that the'periodic .removal of the cyanidv fromthe reaction residues is further of advantage in sofar as thef` i'actual formation of the :former is concerned, 'since if the cyanid 1sallowed to collect 1n the 'reactive mass, the pores or'intersticesbetween the particles of catalytic material be- 7 come vclogged orchoked to some measure, the

liquid 'cyanid being drawn up by capillarity along with the liquidcarbonate and, at least,

diluting the reactive iilm of the latter, if,"

of suchinterstice."

only an extended 'catalytic'solution Surface,

.indeed the mass of 'liquid in aV given inter; istice'does'not"`altogether prevent "th'e'facces'sjh-'l of nitrogen' tothe portions of the catalytic- .solution surfacelfA yiifhifc'zh`v'constitute theY Walls f I have explained at considerable` length incompanion application- .(Seralvfrllo. 726,924) the advantage ofniaintainingnot j alkali'inetal present in or liberated ronithef"compound of-the same which constitutes the source of this metal, e. g.sodium'carbnate"l (or the' alkali metalsupplied as such) may'l reacttogether tofor-In the'cyanidibut haveA also dwelt upon the vdesirabilityof mainfj-m taining a considerable portion 'of this 'surface' relativelyfree from the liquid carbonate', or

the like, so 'that .the nitrogen and .alkali l metal, may'have anopportunity/to lreach said surface; they latter at most, in so vfar aslsaid portionv is concerned, being covered vmerely by a thin lm of theliquid source of' r the alkalimetal, when' such vsource i'sus'ed.

The alkali metal is eiciently liberatedfrom"l` or adjacent'to 'thisextended film surface,

' while the liquid carbonate or like compound used .is 'alsovaporized,"a'nd this'vapor thereafter participates in .th'e reaction;either' A liberate alkali metal. The term vapor `as .used in certainofthe appended claims isA hence to be regarded as o sufiicient breadthtoco'ver both alkali metal va or and that of a compound of such or asimilarly. acting metal.; while the term' alkali metal, or correspondinterm, u lessd'otherwise character-.l ized, is'to, eregar .as =ofsucientscopev doing so directly, or 'by first decomposng'to.

tocover'both/ree metaljand the element, per

'aeres present, at leastl initially, in a com. pound of su f metal.Similar remarks apply. ff when? and. wnitrogen. -.u1.11eSS use . 70tioxro'fcyanid. 'Thus"` the stages of 'the reformed, to 'subsequentlyagaln` be convert-l c Abonate, or the like, will be diluted'by the.already formedcyanidlso that the produc'"' these words beA 'otherwisequalified the.' A claims. I herein point out the further ad vantage ofremovinthebulk of the cyanid from said 'surface or 4 the same reasonthat the bulk of the carbonate, or the like is removed, and also for thereason, which I have ,above indicated, that. the alkali metal cartion offurther c nid isretarded. Further, at least until t e-iron is thoroughlycarburized, owing to the reversibility of the reaction, a certain-Ipercentage of the c anid present in the reactive mass' is alwa s eingdecomposed, the carbonate or'theli ebeing edto cyanid. By thusr'emovingthe cyanid from the zone of the reaction, therefore,the

process as a whole is rendered more -`efii`cient and` the production ofcyanid per unit of time, expedited. The application ofcyanid'distillation, particularly at reduced pressure,

to my former process is therefore extremely beneficial from a numberl ofstandpoints,'not

the least important of which is the rendering possible of the economicalseparation of the cyanid from the `reactive mass at suchtem-vperatur'es-as to 'permit of the use commer.-

cially of copper or of highly carburized iron Y apparatus,the-distillation being leffected,

without undue care, at temperatures below .the eutectic point of thelatter. It obviates AAlixiviation with its .consequent impairment(temporary lor permanent) of the eiliciency of the reactive residue, andit obviates the necessity,'where lixiviation is resorted to, ofevaporatmg ofor otherwise removing the water which holds the so removedcyanid in solution. It also renders 'possible the etilcient use of suchcatalytic4 agents' (in lieu of the iron) as magnesium or lithium,becauseA with these latter lixiviation cannot well be tion of ammonia fromsodium cyanid through the cyanate according to the equaemployed owingl.to the action of watery thereon. -i

The separation of cyanid from the residues of the reaction, bydistillationA (particularly.

im. lucuo) also makes practical the prepara- Here, it is toi-be notedthat the process yields far 'more nitrogen, equation 7 than it can use,also ammonia and carbon dioxid are obtained according to equation 8. The.latter`Y-`lv substances are exactly what is required for the ammoniasodaprocess or for making' certain amid-like fertilizers.- These tworeactions are each practically instantaneous and afford ameans ofgetting ammonia from cyanids without'the great disadvantage of oxidationof the iron or carbon'by steam or air, the'decompositionhof ammonia `ata heat, the-slower action of steamat lower to contaminate the'ammonia. A

' Having thusdescribed myinvention what I claim is:

1. The process of fixing .nitrogen comprises bringing initially freenitrogen' 4into contact wlth an extended surfacel of molten materialcomprising, as one of the v constituent elements thereof, ametal capableof 'combining with nitrogen arid carbon and of acting as the base of astable-'cyanogen comp'ound under the temperaturegbonditions f -8!) saidmateria-'1, combining sald metal and of the operation, liberating saidmetal 4from nitrogenwith the carbon4 contained in an extended surface ofcatalytic material hav'- ing carbondissolvedtherein, to form said'cyanogen compound, and maintaining a largeextent of said surface.substantially free from the bulk of said molten material, whereby toafford freeaccesslof the nitrogen .-and metal molecules thereto, saidlast mentioned step of the process bein effected in A,part by'dlstilling-o, durin t e course vof theoperationa portion at east of theso 'formed cyanogen compound, at a tempera- .tur belowfthat of theeutectic point of said carbon containing catalytic material.

temperatures, or the formation of cyanogen.

2.a" The process of xing nitrogen which compound under the temperatureconditions f the operation,l liberating said metal from said material,combining said metal and nitrogen withthe carbon contained in anextended surface of catalytic material having4 carbon dissolved therein,to form said cyanogen compound and maintaining a large extent of saidsurface substantially free from the bulk of said molten materiah,l

whereby to aord free access 'of the nitrogen andfmetal moleculesthereto, said last mentioned step of the process being-eiected in partby distilling-oif, during the course of theoperation a portion at leastof .the so formed cyanogen compound;4

3." The process of fixingnitrogen which comprises brinvinginitially-free nitrogen into -contact with materialj' comprising, as

one of the constituents. thereojfg'fa 'metal vcapable of combininglwith'fr'iitrogen-- and' carbon andof acting'as thefbas'eofiastable'cyanogen compound under thctempriitir'e conditions of the operation,combining said metal and nitrogen with the carbon con-`v tained in anextended surface of catalytic material having carbon dissolved'ther-ein, to form said cyanogen compound, and maintaining alargeextentzo'f said surface free from vany` suoli amount of molten materialfas would prevent relatively free access tilling-ol, during the course ol LA ' metal and nitrogen with the carbon contained in an extendedsurface of catalytic materialhaving carbon dissolved therein, to formsaid cyanogcn compound, and maintaining a large extent of said surfacefree from any such amount ofi molten .material .as would vpreventrelatively free access thereto of reactive .gaseous matter includingVsaid free nitrogen, said last 'mentioned step of the process .beingeffected in part by vaporizing ofi", during the course ofl theoperation, a portion at least of the so formed eyanogen compound.

'In testimony qwhereoflha've aixed my V signature, in thepresence of twowitnesses..

JOHN nfBUcHER.

Witnesses:

THOMAS H. RoBEn'rs.;

